The invention relates to a member provided with an external screw thread.
As a function of the intended use and in the case of screw connections, it is important to a greater or lesser extent to prevent loosening by means of a rotation preventing means. It is therefore inevitable e.g. in dental prosthetics, for screw connections to have a detachable, but firm seating. Loosening must in particular be prevented in the case of parts which are directly screwed into an implant, such as e.g. implant extensions, implant posts, attachment posts, etc., or in the case of screws used for fixing crowns, bridges and other structures in dental prosthetics.
German patent 39 17 690 already discloses for this purpose a spacer sleeve stop, which has a ring nut-like construction and which can be screwed by means of an internal lock thread with a much smaller pitch than the insert thread of a spacer sleeve bottom onto an external thread provided on the bottom close to the distal edge. Thus, the member, the spacer sleeve top and spacer sleeve bottom can be locked and braced together, which prevents rotation of both the spacer sleeve bottom which receives the implant post and the spacer sleeve top.
German patent application P 40 28 855.2 (addition to German patent 39 17 690) describes a corresponding further development of the rotation-prevented individual tooth implant according to the main patent, in which rotation is reliably prevented by simpler means using positive engagement chambers or members.
Both from the aforementioned prior art regarding single tooth implants and other members provided with external screw threads in the field of dental prosthetics and the like, no rotation prevention means is known which can do without some type of positive engagement. As a result the construction of such rotation prevention means in the given dimensions of the implant or prosthetics is often complicated or relatively expensive.